At least 17 people were reportedly killed and 13 severely injured when the bus in which they were travelling rolled down a deep gorge in Nagaland's Wokha district early Sunday morning, official sources said in Kohima.

The Nagaland State Transport (NST) night super bus coming from border district of Tuensang to Kohima via Wokha, skidded off the road and rolled down a deep gorge at Kontsunyu village, 11 km from Wokha town, killing 17 people on the spot.

Reports reaching Kohima said the district administration has engaged the police and Assam Rifles personnel in rescue operation and 13 of the injured have been admitted to Wokha civil hospital and private nursing homes.

Meanwhile, the condition of six of the injured is serious. They were being evacuated to Naga hospital in Kohima on a chopper arranged by the district administration and Assam Rifles.

The cause of the accident was yet to be ascertained and investigations were on, police said.